Thanks all for your responses.
My owner's instructions request the wedges I mentioned. Of course I( have contacted riggers to avail.
Wood wedges are a second possibility of which I am aware. There are special requirements in terms of hardness for these wedges so I was trying to avoid the online rubber wedges that did not specify their hardness.
I will continue to search for the wedges I mentioned. If any Swan owners know of a supply opportunity for them, please let me know.
Thanks again to those who have attempted to help.
Rich